std::basic_istream::unget

From Cppreference

Makes the most recently extracted character available again.

First clears eofbit, then constructs a std::basic_istream::sentry object with noskipws set to true. Afterwards, if good(), calls setstate(failbit) and returns. Otherwise, calls rdbuf()->sungetc().

If rdbuf()->sungetc() returns Traits::eof(), calls setstate(badbit).

In any case, sets the gcount() counter to zero.

[edit] Parameters

(none)

[edit] Return value

*this

[edit] Example

#include <sstream>
#include <iostream>
int main()
{
    std::istringstream s1("Hello, world.");
    char c1 = s1.get();
    if(s1.unget())
    {
        char c2 = s1.get();
        std::cout << "Got: " << c1 << " got again: " << c2 << '\n';
    }
}

Output:

Got: H got again: H

[edit] See also